Form 8-K

8-K — Aptevo Therapeutics Inc.

Accession: 0001193125-26-221593

Filed: 2026-05-13

Period: 2026-05-13

CIK: 0001671584

SIC: 2834 (PHARMACEUTICAL PREPARATIONS)

Item: Results of Operations and Financial Condition

Item: Financial Statements and Exhibits

Documents

8-K — apvo-20260513.htm (Primary)

EX-99.1 (apvo-ex99_1.htm)

GRAPHIC (img237228349_0.gif)

XML — IDEA: XBRL DOCUMENT (R1.htm)

8-K

8-K (Primary)

Filename: apvo-20260513.htm · Sequence: 1

8-K

false000167158400016715842026-05-132026-05-13

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 13, 2026

APTEVO THERAPEUTICS INC.

(Exact name of Registrant as Specified in Its Charter)

Delaware

001-37746

81-1567056

(State or Other Jurisdiction

of Incorporation)

(Commission File Number)

(IRS Employer

Identification No.)

2401 4th Avenue

Suite 1050

Seattle, Washington

98121

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: (206) 838-0500

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading

Symbol(s)

Name of each exchange on which registered

Common Stock, $0.001 par value

APVO

The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition.

On May 13, 2026, Aptevo Therapeutics Inc. (the “Company”) issued a press release announcing its financial results for the period ended March 31, 2026. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated herein by reference.

The information in this report, including the exhibit hereto, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Act of 1934, as amended, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission (the “SEC”) made by the Company, whether made before, on or after the date hereof, regardless of any general incorporation language in such filing, except as shall be expressly set forth by specific reference in such filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.

Description

99.1

Press Release dated May 13, 2026.

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

APTEVO THERAPEUTICS INC.

Date:

May 13, 2026

By:

/s/ Daphne Taylor

Daphne Taylor

Senior Vice President and Chief Financial Officer

EX-99.1

Filename: apvo-ex99_1.htm · Sequence: 2

EX-99.1

Exhibit 99.1

Aptevo Therapeutics Provides a 1Q26 Business Update; RAINIER on Track for 2026 Completion and Phase 2 Dose Selection

Mipletamig continues to perform, delivers 87% clinical benefit and 81% remission in frontline AML, with no CRS in frontline patients

Executive leadership transition complete. Jeff Lamothe appointed CEO; Marvin White assumes Executive Chair

$60 million equity line of credit enhances financial flexibility and extends access to capital through achievement of key catalysts into 2029

SEATTLE, WA – May 13, 2026 – Aptevo Therapeutics Inc. (Nasdaq: APVO), a clinical-stage biotechnology company focused on developing novel immune-oncology therapeutics based on its proprietary ADAPTIR™ and ADAPTIR-FLEX™ platform technologies, today provided a business update.

“Aptevo is entering a defining period as a company, supported by growing clinical momentum, a committed leadership team, and a pipeline with the potential to create significant long-term value,” said Jeff Lamothe, President and Chief Executive Officer of Aptevo. “Mipletamig continues to generate compelling frontline AML data, combining strong remission activity with a differentiated safety profile with the potential as an important addition to standard-of-care therapy. At the same time, we are continuing to advance our next generation of multispecific immunotherapy programs, including our emerging trispecific candidates, which are designed to address complex solid tumors through differentiated mechanisms and targeted immune modulation. We believe our ADAPTIR and ADAPTIR-FLEX platforms position Aptevo to expand into multiple high-value areas of oncology innovation. With meaningful clinical and strategic milestones ahead, financial flexibility to support execution, and increasing validation of multispecific approaches throughout the industry, we believe we are building from an increasingly strong foundation for future growth and value creation.”

RAINIER trial on track for completion and Phase 2 dose selection by year end.

•

Mipletamig continues to generate strong data in frontline acute myeloid leukemia (AML) in combination with venetoclax + azacitidine. Across 31 evaluable patients (includes data through RAINIER Cohort 5, plus 4 patients from the previously completed dose expansion trial), the data has demonstrated continued efficacy, including:

•

87% clinical benefit rate* demonstrates broad anti-leukemia activity and blast reduction across response categories

•

81% CR or CRi (remission), compared to 66.4% in the Phase 3 VIALE-A trial**

•

65% achieved CR (complete remission), compared to 37% in the Phase 3 VIALE-A trial**

•

No cytokine release syndrome (CRS), a common and often dose-limiting toxicity associated with similar therapies, has been observed in frontline patients to date

The data also show that 52% of patients who achieved CR/CRi had blast reductions that reached the important measurable residual disease-negative level, a result that is typically associated with stronger, more durable responses.

As the dataset continues to expand, efficacy and safety outcomes continue to deliver favorable results, further supporting mipletamig’s potential in the frontline setting.

*Clinical benefit rate: complete remission (CR), complete remission with incomplete hematologic recovery (CRi), and partial remission (PR)

**Phase 3 VIALE-A trial evaluating venetoclax plus azacitidine in frontline intent-to-treat AML patients who were ineligible for intensive induction chemotherapy, the reported composite CR/CRi rate was 66.4%, and the CR rate was 37% (DiNardo et al., New England Journal of Medicine, 2020).

Completed Leadership Transitions; Company Poised for a Defining Year

Aptevo entered 2026 with purposeful momentum, highlighted by a planned executive leadership transition designed to support the company’s next phase of growth. Jeff Lamothe was appointed President and Chief Executive Officer, while Marvin White transitioned to Executive Chair. The move reflects continuity in strategy while positioning the organization for focused execution across clinical development, capital strategy, and long-term value creation.

Q1 2026 Cash Position

Aptevo had cash and cash equivalents totaling $14.5 million as of March 31, 2026. During the first quarter of 2026, the company raised $0.9 million, net, under the company’s Standby Equity Purchase Agreements (SEPAs) with Yorkville. For additional APVO financial information and complete access to the company’s filings, click here.

Enhanced Financial Flexibility Supports Upcoming Catalysts

During the quarter, Aptevo secured a $60 million SEPA, providing meaningful access to capital and extending financial flexibility as the company advances toward planned milestones. Management believes the facility better positions Aptevo to execute strategically, support ongoing development programs, and approach future opportunities from a position of greater strength.

About Aptevo Therapeutics

Aptevo Therapeutics Inc. (Nasdaq: APVO) is a clinical-stage biotechnology company focused on developing novel bispecific and trispecific immunotherapies for the treatment of cancer. The company has two clinical candidates. Mipletamig is currently being evaluated in RAINIER, a two-part Phase 1b/2 trial for the treatment of frontline acute myeloid leukemia in combination with standard-of-care venetoclax + azacitidine. Mipletamig has received orphan drug designation

("orphan status") for AML according to the Orphan Drug Act. ALG.APV-527, a bispecific conditional 4-1BB agonist active only upon simultaneous binding to 4-1BB and 5T4, is being co-developed with Alligator Bioscience and was most recently evaluated in a Phase 1 clinical trial for the treatment of multiple solid tumor types likely to express 5T4. The company has six preclinical candidates designed to target a range of solid tumors. All pipeline candidates were created from two proprietary platforms, ADAPTIR and ADAPTIR-FLEX. The Aptevo mission is to improve treatment outcomes and transform the lives of cancer patients. For more information, please visit www.aptevotherapeutics.com.

Safe Harbor Statement

This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, including, without limitation, Aptevo’s expectations about the activity, efficacy, safety, tolerability and durability of its therapeutic candidates and potential use of any such candidates, including in combination with other drugs, as therapeutics for treatment of disease, its expectations regarding the effectiveness of its ADAPTIR and ADAPTIR-FLEX platforms, statements related to the progress of Aptevo’s clinical programs, including statements related to anticipated clinical and regulatory milestones, whether further study of mipletamig in a Phase 1b dose optimization trial focusing on multiple doses of mipletamig in combination with venetoclax + azacitidine on a targeted patient population will continue to show remissions, whether further study of mipletamig in a Phase 1b dose-optimization trial will continue to report a favorable safety profile, let alone no instances of cytokine release syndrome, whether Aptevo’s final trial results will vary from its earlier assessment, whether Aptevo’s strategy will translate into an improved overall survival in AML, especially among patient subgroups with poor prognosis, whether further study of ALG.APV-527 across multiple tumor types will continue to show clinical benefit, the possibility and timing of interim data readouts for ALG.APV-527, development and continued development of Aptevo's current and potential future molecules, including its trispecific candidates, statements related to Aptevo’s cash position and balance sheet, statements related to Aptevo’s ability to generate stockholder value, whether Aptevo will continue to have momentum in its business in the future, statements regarding Aptevo’s leadership transition, strategic direction, business outlook, expected future performance and any other statements containing the words “may,” “continue to,” “believes,” “knows,” “expects,” “optimism,” “potential,” “designed,” “promising,” “plans,” “will” and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based on Aptevo’s current intentions, beliefs, and expectations regarding future events. Aptevo cannot guarantee that any forward-looking statement will be accurate. Investors should realize that if underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results could differ materially from Aptevo’s expectations. Investors are, therefore, cautioned not to place undue reliance on any forward-looking statement.

There are several important factors that could cause Aptevo’s actual results to differ materially from those indicated by such forward-looking statements, including a deterioration in Aptevo’s business or prospects; further assessment of preliminary or interim data or different results from later clinical trials; adverse events and unanticipated problems, adverse developments in clinical development, including unexpected safety issues observed during a clinical trial; and

changes in regulatory, social, macroeconomic and political conditions. For instance, actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the uncertainties inherent in the results of preliminary or interim data and preclinical studies being predictive of the results of later-stage clinical trials, initiation, enrollment and maintenance of patients, and the completion of clinical trials, the availability and timing of data from ongoing clinical trials, the trial design includes combination therapies that may make it difficult to accurately ascertain the benefits of mipletamig, expectations for the timing and steps required in the regulatory review process, expectations for regulatory approvals, the impact of competitive products, our ability to enter into agreements with strategic partners or raise funds on acceptable terms or at all and other matters that could affect the availability or commercial potential of Aptevo’s product candidates, business or economic disruptions due to catastrophes or other events, including natural disasters or public health crises, geopolitical risks, including the current war between Russia and Ukraine, the United States and Iran and any other military event that could evolve out of any of the current conflicts, and macroeconomic conditions such as economic uncertainty, imposition of tariffs, rising inflation and interest rates, continued market volatility and decreased consumer confidence. These risks are not exhaustive, Aptevo faces known and unknown risks. Additional risks and factors that may affect results are set forth in Aptevo’s filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K for the fiscal year ended December 31, 2025, and its subsequent reports on Form 10-Q and current reports on Form 8-K. The foregoing sets forth many, but not all, of the factors that could cause actual results to differ from Aptevo’s expectations in any forward-looking statement. Any forward-looking statement speaks only as of the date of this press release, and, except as required by law, Aptevo does not assume any obligation to update any forward-looking statement to reflect new information, events, or circumstances.

CONTACT:

Miriam Weber Miller

Vice President, Investor Relations & Corporate Communications

Aptevo Therapeutics

Email: IR@apvo.com or Millerm@apvo.com

Phone: 206-859-6628

GRAPHIC

Filename: img237228349_0.gif · Sequence: 3

Binary file (2792 bytes)

Download img237228349_0.gif

XML — IDEA: XBRL DOCUMENT

XML

Filename: R1.htm · Sequence: 6

v3.26.1

Document And Entity Information

May 13, 2026

Cover [Abstract]

Document Type

8-K

Amendment Flag

false

Document Period End Date

May 13, 2026

Entity Registrant Name

APTEVO THERAPEUTICS INC.

Entity Central Index Key

0001671584

Entity Emerging Growth Company

false

Entity File Number

001-37746

Entity Incorporation, State or Country Code

Entity Tax Identification Number

81-1567056

Entity Address, Address Line One

2401 4th Avenue

Entity Address, Address Line Two

Suite 1050

Entity Address, City or Town

Seattle

Entity Address, State or Province

Entity Address, Postal Zip Code

98121

City Area Code

(206)

Local Phone Number

838-0500

Entity Information, Former Legal or Registered Name

Not Applicable

Written Communications

false

Soliciting Material

false

Pre-commencement Tender Offer

false

Pre-commencement Issuer Tender Offer

false

Title of 12(b) Security

Common Stock, $0.001 par value

Trading Symbol

APVO

Security Exchange Name

NASDAQ

- Definition

Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

+ References

No definition available.

+ Details

Name:

dei_AmendmentFlag

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Area code of city

+ References

No definition available.

+ Details

Name:

dei_CityAreaCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Cover page.

+ References

No definition available.

+ Details

Name:

dei_CoverAbstract

Namespace Prefix:

dei_

Data Type:

xbrli:stringItemType

Balance Type:

Period Type:

duration

- Definition

For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

+ References

No definition available.

+ Details

Name:

dei_DocumentPeriodEndDate

Namespace Prefix:

dei_

Data Type:

xbrli:dateItemType

Balance Type:

Period Type:

duration

- Definition

The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

+ References

No definition available.

+ Details

Name:

dei_DocumentType

Namespace Prefix:

dei_

Data Type:

dei:submissionTypeItemType

Balance Type:

Period Type:

duration

- Definition

Address Line 1 such as Attn, Building Name, Street Name

+ References

No definition available.

+ Details

Name:

dei_EntityAddressAddressLine1

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Address Line 2 such as Street or Suite number

+ References

No definition available.

+ Details

Name:

dei_EntityAddressAddressLine2

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Name of the City or Town

+ References

No definition available.

+ Details

Name:

dei_EntityAddressCityOrTown

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Code for the postal or zip code

+ References

No definition available.

+ Details

Name:

dei_EntityAddressPostalZipCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Name of the state or province.

+ References

No definition available.

+ Details

Name:

dei_EntityAddressStateOrProvince

Namespace Prefix:

dei_

Data Type:

dei:stateOrProvinceItemType

Balance Type:

Period Type:

duration

- Definition

A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityCentralIndexKey

Namespace Prefix:

dei_

Data Type:

dei:centralIndexKeyItemType

Balance Type:

Period Type:

duration

- Definition

Indicate if registrant meets the emerging growth company criteria.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityEmergingGrowthCompany

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

+ References

No definition available.

+ Details

Name:

dei_EntityFileNumber

Namespace Prefix:

dei_

Data Type:

dei:fileNumberItemType

Balance Type:

Period Type:

duration

- Definition

Two-character EDGAR code representing the state or country of incorporation.

+ References

No definition available.

+ Details

Name:

dei_EntityIncorporationStateCountryCode

Namespace Prefix:

dei_

Data Type:

dei:edgarStateCountryItemType

Balance Type:

Period Type:

duration

- Definition

Former Legal or Registered Name of an entity

+ References

No definition available.

+ Details

Name:

dei_EntityInformationFormerLegalOrRegisteredName

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityRegistrantName

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityTaxIdentificationNumber

Namespace Prefix:

dei_

Data Type:

dei:employerIdItemType

Balance Type:

Period Type:

duration

- Definition

Local phone number for entity.

+ References

No definition available.

+ Details

Name:

dei_LocalPhoneNumber

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 13e

-Subsection 4c

+ Details

Name:

dei_PreCommencementIssuerTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14d

-Subsection 2b

+ Details

Name:

dei_PreCommencementTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Title of a 12(b) registered security.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b

+ Details

Name:

dei_Security12bTitle

Namespace Prefix:

dei_

Data Type:

dei:securityTitleItemType

Balance Type:

Period Type:

duration

- Definition

Name of the Exchange on which a security is registered.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection d1-1

+ Details

Name:

dei_SecurityExchangeName

Namespace Prefix:

dei_

Data Type:

dei:edgarExchangeCodeItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14a

-Subsection 12

+ Details

Name:

dei_SolicitingMaterial

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Trading symbol of an instrument as listed on an exchange.

+ References

No definition available.

+ Details

Name:

dei_TradingSymbol

Namespace Prefix:

dei_

Data Type:

dei:tradingSymbolItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Securities Act

-Number 230

-Section 425

+ Details

Name:

dei_WrittenCommunications

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration